Abstract: According to the daily precipitation observation data during 1918-2010 in Tianjin, the long-term tendency of precipitation and extreme precipitation indexes are analyzed. The results show that the annual rainfall and precipitation days have significant interannual fluctuations, but without significant tendencies. The rainfall and precipitation days have displayed a decreasing tendency since 1980, and their variances also become smaller. The rainfall significantly increased in autumn, decreased in summer, and only has small changes in winter and spring. In 1918-2010, all extreme precipitation indexes exhibited no notable linear variation tendency but with large interannual fluctuations. After the1990s, the precipitation intensity was smaller than normal, but showed a slow increasing tendency. The number of heavy rain days was also in a low stage, and its contribution rate to the total precipitation was smaller than normal, and showed a reducing tendency. The maximum rainfall of consecutive 5 days increased significantly in autumn, which reduced the occurrences of autumn drought. The longest consecutive dry days often happened in winter and spring and have increased in recent years.

Key words: precipitation, extreme precipitation indexes, climate change, Tianjin